It's not necessary, unless the toenails get long enough to stab or hook Monster's own skin anywhere. Usually we want to trim the nails for our own comfort, to prevent the deep scratches on our skin.

You are a long-term iguana owner, so I don't want to just presume you could use some advice on nail clipping. But it might help, so here it is:

This is a no-risk way to clip his nails. I learned how to trim the tiny sharp nails at the ends of the claws without hurting my iguanas, by reading the following article*. It's easy to do if Monster lets you hold one toe at a time. Wrap him in a towel so his eyes are covered and pull one foot out at a time to do the trimming. Snip 1/8 inch off the tip of the needle-pointed nails. He won't feel that at all, unless the pressure reminds him of the time it hurt. Just keep pulling the toe into position until you have a good shot at clipping. Afik there are no special clippers for iguanas.